One thing to think about is: do you get to decide which to use or will you have to use what present and future employers will want. It seems that areas have a defacto standard. TDS is the standard here but i prefer the D'zign.

The D'zign will hold more points per given ram card size and it uses, not wastes, the resident memory. It's slope staking routine is the best on the market for the 48 series. I don't know if the Card version of D'zign you are talking about will hook up to the instrument you will be using or not. This is also something to think about with any iteration of TDS. They could not look into the future and anticipate newer guns.

Another thing to think about is support. Nowadays, the new TDS just can't be bothered talking to people who have already bought their product. With D'zign; you can call up and Phylis will talk you through any problem. On an SX, anything below ver 3.2 of TDS will have bugs and on a GX, get ver 4.12 or above.